1. Field of the Invention
The present invention relates to a process cartridge integrally including at least an image bearing member and developing means, and an image forming system within which such process cartridge can be removably mounted. The image forming system may be a copying machine, facsimile, printer and the like.
2. Related Background Art
Conventionally, process cartridges integrally including a photosensitive member, a charger, developing means and the like as a unit, which can be removably mounted within an image forming system, have been widely used in order to improve the maintenance of the image forming system. However, various members or elements (for example, a charger wire, photosensitive drum, developing roller, toner and the like) used in such a process cartridge have different service lives. Thus, by adopting the exchange of a process cartridge, maintenance has been improved.
On the other hand, it is considered that the whole developing device including a toner containing portion can be removable with respect to the process cartridge so that the toner can be replenished frequently, in view of the replenishment of the toner having the least service life among the elements used in the process cartridge. However, this method is not economical since the whole developing device, including not only the toner containing portion but also a developing roller having a service life which has not yet been expired, must be exchanged. Further, since the developing roller must be positioned with respect to the photosensitive drum whenever the developing device is exchanged, the operability is remarkably worsened.